Oxford Union's decision to invite the controversial historian David Irving to take part in a debate has led to threats of a boycott.

Mr Irving, described by a High Court judge as racist and sympathetic to right-wing extremists, is due to speak on Thursday in a motion "this house would restrict the free speech of extremists".

Mr Irving has controversial views on the Nazi persecution of the Jews

But general secretary of the Association of University Teachers (AUT), David Triesman, said giving Mr Irving a platform would only inflame racial tension and he called for an "academic boycott" of the union.

In a letter to the president of the union, Amy Harland, Mr Triesman said: "As an
educator, a trade unionist and a passionate advocate of the notion of tolerance
and inclusion, I cannot accept your contention that it is correct to allow Mr
Irving a platform at such a prestigious institution as the union".

It would not be possible for the UK to develop as a multicultural and free
society while the views of people like Mr Irving were offered refuge by
important institutions like the union, Mr Triesman said.

"If the Oxford Union feels compelled to proceed with the invitation I must
inform you that this would leave me with no other option than to call for an
academic boycott of the union both in this country and from amongst the academic
community and other trade unions throughout the world."

Lost libel case

In the High Court last year, Mr Irving, author of Hitler's War and a biography of Goebbels, lost his libel battle over a book by academic Deborah Lipstadt which described him as a "Holocaust denier".

The judge Mr Justice Gray found that Mr Irving was "an active Holocaust denier; that he is anti-Semitic and racist and that he associates with right-wing extremists who promote neo-Nazism".

Mr Triesman says the decision may inflame racial tension

Oxford Union insisted Mr Irving was not being invited to voice his views about the Holocaust and said the debate would only be cancelled if the police warned of a
"substantial risk" to public safety.

A union spokesman voiced surprise the AUT's protest, saying they had not been approached by the organisation.

"If they were so concerned, why did they not take the opportunity to contact
us - we would have been more than happy to explain our reasoning," he said.